The idea: Create something that can punch things as hard as possible without power attack.

The build:

Swashbuckler 3Factotum 8Kensai 9

Now, Swash 3 gets us our Int bonus to damage. In the long run we want our Int to be in the ballpark of 16 + 5 (from levels) and then +5 (from an item).

Factotum 8 gets us two things, the capacity to take an extra standard action and our Int bonus to damage (again) so we're still looking for at least the above result of 26 total.

Kensai 9 will help us get our fists enchanted, with the two key points being the Collision enhancement (a +2 equivalent that flat out adds 5 damage) and a +5 natural enhancement degree for yet another 5 there. It further gives us Power Surge, which lets us spend a standard action to get several rounds of +8 strength.

Add this up and we're looking at 14 + 8 + 6 strength for a total of 28Int will be 16 + 5 + 5 for a total of 26 and this bonus gets doubledThen we have the Collision ability and the enhancement adding a flat +10

So we're looking at 9 + (8x2) + 10 for starters. We have 35 damage flat added every single hit.